A knife attack on the grounds of a Benedictine abbey in southern Poland left one person dead and at least four injured, local media reported on Thursday.

A 31-year-old Ukrainian citizen was detained after the attack at the Benedictine Abbey in Jaroslaw, police said in a statement.

The motives behind the attack were not immediately clear.

The attack happened at a Benedictine Sisters monastery on the grounds of the abbey, local media said.

“We are aware that Father Stanisław has passed away and Father Marek is in serious condition; there are other casualties, but we do not have further details,” Sister Barbara Dendor told state broadcaster TVP Info.

“When I arrived, there was total panic; young people who had come out of the center witnessed it — they were saying, ‘Some madman, some madman!’” she said.

Police said they were on the scene investigating the incident.